Method for treating molds used in the art o electrotyping.



G. E. DUNTON. METHOD FOR TREATING MOLDS USED IN THE ART OF ELECTROTYPING. APPLIGATION FILED JUNE 23,1914.

1, 1 28,427, Patented Feb. 16, 1915.

Z SHEETS-SHEET 1.

G. E. DUNTON.

METHOD FOR TREATING MOLDS USED IN THE ART OF ELEGTROTYPING;

' APPLICATION FILED JUNE 23,1914.

1,128,427, 1 Patented Feb.16, 1915.

others skilled in the art nal form composed of types,

ED srarns PATENT orrioal GEORGE E. DUNTON, or NEW YORK, N. Y.

METHOD FOR TREATING MOLDS USED IN THE ART OF ELECTROTYPING.

Specification of Letters Patent.

Patented Feb. 16, 1915.

To all whom it may concern:

Be it known that I, GEORGE E. DUNTON, residing at New York city, in the county of New York and State of New York, a citlzen of the United States, have invented a certain new and useful Improved Method for Treating Molds Used in the Art of Electrotyping; and I do hereby declare the f ollowing to be a full, clear, and exact descrlption of the invention, such as will enable to which it pertains to make and use the same.

My invention relates to an improved method for treating'molds used in the art of electrotyping and more particularly to insulating the mold from its molding pan and thereby preventing any electrical connection between them.

In the art of electrotyping it is necessary to use a thin sheet of some metal as a back or base for the wax molds. These thin sheets of metal are commonly called pans creases and are generally made from an alloy of lead, tin and antimony known as electrotype metal, even brass sheets have been used, and are usually about one-eighth to three sixteenths of an inch in thickness. These metal pans or cases are laid fiat upon 'iron tables or slabs, hot wax is poured over them and allowed to cool, strips of iron having been.

placed around the edge to confine the wax. After the wax has been poured onto these pans or cases, on one side, they are known as filled cases or pans and are what the electrotyper uses to take the impression on or make his mold in. The wax surface is brushed over with black lead and the origiillustrative cuts or whatever is desired to be electrotyped is pressed into this mold. To receive the desired deposit or cause the deposit on the wax it isnecessary to make the surface of the waxconductive, meaning that the'surface of the wax must be made metallic, so-

that when the mold is placed in the electrolytic bath it shall perform its function as the cathode in the electrical'circuit of which it becomes apart. -It is desirable, however, that only the-surface of the wax shall be connected to or form a part of the electrical circuit. To this end especially devised insulating hooks are. provided for hanging the pan or case carrying the wax mold in the electrolytic bath and these hooks make no 'electrical connection between the metallic connection, if made,

although copper and pan or case and the electrical circuit but they connect the surface of the wax mold with the said circuit.

Considerable care has to be exercised and elaborate pains taken to prevent any electrical connection between the surface'of the Wax mold and the metal pan or case as this would defeat the object of the insulating hooks and carry the deposit of metal over onto the exposed back of the pan or case thus wasting the metal, electricalenergy and deflecting the deposit from the electrotype. In bla'ckleading the surface of a wax mold it is impossible to confine the coating of.

black lead to the surface of the wax mold alone as it will, no matter how careful you are, work over the edges of the wax mold onto the back of the pan orcase, thus electrically connecting the surface of the wax mold with the metal pan or case.

My invention has for its object to dispense with the old methods which have been found unsatisfactory and provide an improved method by wh'ich portions of a mold and its molding pan are rendered non-conductive to electricity.

It further has for its object to prov de a method for treating the edges and margins of a mold and the edges and back of a mold ing pan or case with an insulating substance whereby the treated portions are rendered non-conductive.

It further has for its object to provide a method of heating aninsulating substance and applying it to a mold and its molding pan or case. 7 I

It further has for its object to provide a method which is simple, easy to practice and which effects a great saving of time and labor and produces perfect results.

Referring to the drawings which illustrate one form of apparatus for carrying out or performing my method Figure 1 is a front elevation, partly in section. Figs.

2,3, and 4, fragmentary detail views, partly I I I in section, showing the different steps practised by my method in .treating the mold and the molding pan or case. Fig. 5 a central longitudinal section of a mold and its molding pan or case after being treated by my method. i f

In the drawings in which similar reference characters denote similar parts throughout the several views, 1 represents the meltingpot of the apparatus, in which wax or other insluating substance is adapted to be placed and melted, 2 the supporting legs, 3 a brace or tie for the legs, 4 the fluid insulating substance in said melting pot. The insulating substance is ing through a pair of heating cylinders 5 and 6, which are cast or otherwise formed in the melting pot and extend longitudinally thereof, connected and communicating with one another, at one end, by means of a suitable pipe 7. A steam supply pipe 8 is connected to the cylinder'5 and a steam exhaust or return pipe 9 is connected to the cylinder 6, steam, from a boiler or any other source, is adapted to be supplied to the cylinder 5 and caused to traverse and heat'both of said cylinders 5 and 6, melt the insulating substance and pass out by the pipe 9 and be returned to the boiler. The supply of steam to the cylinders 5 and 6 is regulated by means of a suitable valve 10.

The driving shaft of the apparatus, indicated by 11, is mounted in suitable bearings formed in the opposite ends of the melting pot. and a driving pulley 12 for the shaft 11 is loosely mounted on one end of said shaft and is adapted to be connected by means of a belt to any suitable source of power.

Any suitable clutch, not shown, provided on the shaft 11 for the purpose of throwing the shaft into and out of operation as desired, said clutch being operated by means of a foot treadle 13 operatively connected thereto and, a spiral spring 14 is provided for holding up the foot treadle.

A rotatable brush 15 is rigidly mounted on the dravirig shaft 11 and is designed to be partly immersed or submerged in the insulating substance in the melting pot and to .cause said substance to be taken up, applied and made to cover evenly the back surface of the molding pan.

On the opposite side of the melting pot from the driving shaft 11' a shaft 16 is mounted and on this shaft a roller 17, preferably covered with felt 18, is' mounted which is operatively connected by means of a crossed belt 19 with the driving shaft 11. The cross belt is used to cause the roller '17 to turn or rotate in the opposite direction "from the brush l5. f

At the rear of the melting pot'a receiving rack 21 is'provided for the molds after they have received their coating of insulating substance, said rack having a rim22 and rollers 23 and being supported by means of suitable braces 24 extending upward from the legs of the apparatus.

25 is a mold1n'g pan. made of metal or any other suitable material, which is provided w th a hole 26 for the purpose of receiving the usual hook by which-it is adapted to be suspended in the electrolytic plating bath, 27- the wax mol in which an impression 28 has been made by forcinga form or cut into melted by steam pass- I my b , the mold thereon with the same by pressure and 29 a hole in alinement with the hole 26 of the molding pan. A metal connector strip 30 is embedded to the desired depth in the surface of the wax mold by heating it and applying it to the mold while in a heated state.

31 is the insulating coating covering the edges and margins of the mold and molding pan after the mold has been dipped edgewise into the insulating substance contained in the melting pot and 32 the insulating coating which has beenapplied to the back of'the molding pan or case by means of the brush 15. The arrows 33 show the points where the insulating edge coating connects and merges with the coating on the back of the molding pan or'case.

A flat or other shaped brush may be employed instead of a circular brush for applying the insulating coating to the back of the molding pan or case and instead of the brush being driven by power it may be caused to move or rotate and apply the insulating coating by moving the mold over it and a brush may be substituted for the felt roller if desired and the number of rollers and brushes may be increased or diminished to suit the different requirements of use In carrying out or practising my method, by the apparatus just described, I place the required quantity of insulating substance in the melting pot and after melting it, to the degree desired, by causing steam to enter the cylinders 5- and 6 from the boiler or other source of steam supply through steam supply pipe 8 and after traversing and heat ing the cylinders the steam, or water of condensation, returns through the pipe 9 to the boiler. I then take the mold and pan or case, which have been prepared and blackleaded in the usual manner, and dip them .edgewiseto the required depth in the insulatlng substance in .15 is then rotated by means of the pulley 12 which operates the shaft 11 and the felt covered roller being connected to the brush 15 by means of the crossed belt 19 is also caused to rotate. The molding pan, with fore described, isthen laid horizontally with the back of the molding pan in contact with the rotatable brush, see Fig. 3 of the-drawings, and as it is pushed forward, with the brush rotating'in theopposite direction, said brush applies and distributes the insulating substance over the back of the molding pan and forms an even,'homogeneous coating thereon and the felt covered roller, being rotated in 1 the opposite direction from the brush, not only serves as a guide to the lit edges coated as bemolding pan but applies and smooths the insulating substance on the back thereof and on the completion of the coating the pan and its mold will abut against the rim of the receiving rack and rest on said. rack and its rollers.

Usually it will suffice to pass the molding pan over the rotatable brush and .felt covered roller once to obtain the necessary coating of insulating substance but if found necessary it can be passed over said brush and roller as many times as desired to acquire the requisite coating.

What I claim is 2-- 1. The method of treating molds used 'in the art of electrotyping, consisting in forming a coating of'non-conducting material on a portion of the mold and the back of the molding pan.

2. The method of treating molds used in the art of electrotyping, consisting in forming a continuous coating of non-conducting material on a portion of the mold and the molding pan.

3. The method of treating molds used in the art of electrotyping, consisting in forming a coating of non-conducting material over the back-of the molding pan and the margins surrounding the face of the mold.

4. The method of treating molds used in the art of electrotyping, consisting in forming a coating on the margins of the mold and molding pan and then forminga coating of non-conducting material on the back' of the molding pan and causing it to merge with the first mentioned coating.

5. The method of treating molds used in the art of electrot ping, consisting in insulating the mold rom its molding pan by applying anon-conducting coating to a por- I tion ofthe mold and its molding pan and then applying a non-conducting coating to the back surface of the molding pan which remains exposed and causing it to merge with the first mentioned coating.

6. The method of treating molds used in the art of electrotyping, consisting in melt ing an insulating substance, and causing said melted or fluid insulating substance to be applied to the edges and back of the molding pan and form a continuous coating.

7. The method of treating molds used in the art of electrotyping, consisting in melting an insulating substance, causing said melted or fluid insulating substance to be gradually applied to the back of the molding pan.

8. The method of treating molds used in the art of electrotyping, consisting in dipping portions of the mold and molding pan in a fluid insulating substance and then causing a fluid insulating substance to be applied gradually to the back of the molding pan, not previously coated by the dipping step, thereby insulating the mold from its backing.

9. The method of treating molds used in the art of electrotyping, consisting in coatsisting in applying a coating of Wax to portions .of the molding pans, graphite and wax mold and then applying .a coating of Wax to the exposed back surface of the molding an.

In testimony whereof I aifix my signature in the presence ofltwo Witnesses.

GEORGE E. DUNTON.

Witnesses:

VHENRY BECKER,

Nnzrcrm F. FAmoHILo. 

